Plow



June 2, 1953 K. R. XSCHOLFIELD PLOW 3 Sheets-Sheet 1 Filed NOV. 10, 1947 June 2, 1953 K. R. SCHOLFIELD PLOW 3 Sheets-Sheet 2 Filed Nov. 10, 1947 N QE JNVENTOR. KEITH R. SCHOLFIELD June 2, 195 3 K. RJSCHOLFIELD PLOW 3 Sheets-Sheet 5 Filed NOV. 10, 1947 INVENTOR. KEITH R. SCHOLFIELD a a N R o A Patented June 2, 1953 -;PLOW

KeithfR. Scholfie'ld, "East Moline, "111., assignorto Deere "&"Ccmpany, Moline, Ill., a corporation of "Illin'ois Application November. 1-0, 1947, Serial N 0. 785 001 .Thepresent invention relates generally to agriculturalimplements andmore particularly to implements of the integral or direct connected type, adapted (to he mounted on and supported substantially solely by-a tractor orother propelling unit.

.Ilhephject and .general nature :of the present invention is the provision of .a new and improved implement of the tractor mounted type. More particularly, it is .an important feature of the present invention to .providea tractor mounted implement that is connected in short coupled relation to .the rear of the tractor, whereby the connection 30f the implement to the tractor and the disconnection of the implement therefrom are materially facilitated, and it is yet a. {further feature of this invention to provide quick attachahle connections .further facilitating mounting and tdismounting of the implement. It is also an im,mortar-1t -feature of this invention to provide an implement of this type in which a certain amount of swinging movement of-the implement relative to the tractor is accommodated, whereby the outfit may be used readily and eiiciently in contour workand the like.

,.A- n additional feature of the present invention is the provision of an improved means providing for the lateral adjustment of the implement relative to the tractor so as to accommodate different treads of the tractor, sizes of operating tools, etc., and still further, it is a feature of this invention 11.0 provide :an improved implement of the ground working type. such as, a plow, wherein the plow automatically leveled at the different depths of operation.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of thefollowing detailed description, taken in conjunction with the accompanying drawings.

In the drawings:

Figure l is a plan view of a tractor mounted plow in which the principles of the present invention have been incorporated.

Figure 2-is a side View of the plow shown in Figurel.

Figure 3 is a sectional view taken generally along the line 3--3 of Figure 2.

Figure 4 is .a sectional view taken generally along the line fi:i of Figure 1.

Figure 5 is a perspective view of the bracket that'iorms a part of the means thatrockably connects the plow beam to the tractor drawbar.

Referring now to the drawings, the tractor, which so far as: the present invention is concerned islargely conventional, is indicated inits entirety by the reference numeral I and inifg'eneral'in eludes a main 'ho'dy 2' supported on "from \tiheels (not shown) anii'rear wheels carried "by aresr axle 5. The tractor I also includes a'powerlift unit l? of any suitable type connectedto raise and lower an implement or implements, a'ii'dltb hold 'thei'mplement in d'iiferent positions of adjustment, through an'operating link 5.

In order to "provide for easy and convenient mounting of an implement on the tractor I, I provide a tractor-carried sllhpolting frafii'ewo ik n that is detachahly mounted cm the tra tor but which ordinarily remains as a part the tractor. The framework H includes a tr'aii' supporting angle member l2 having a plum of openings whereby to receive bolt or stud means l3 by which the angle I? ma be rigid-lysecurerl to the rear end of the tractor. Extending up; Wardly and forwardlyfrom the "end portions or thercounting angle I2 are a pair "of supporting arm M which at their upper ends are welded to a transverse sleeve member 15, the ends of which extend laterally outwardly beyondthe slipporting arms M A transverse rockfsha'ft F6 is mountedfor rocking movement in the sleeve iii'e" her it and at its ends carries upwardly and erally rearwardly extending implement "con h l ling arms ll. For operating the rocks'ha'ft' "f6 I provide an operating arm it which at its u per end is connected to the link 6 by anyjsii'itahle means, such as a pivot pin o r bolt l9. T eaters and aft movement imparted by the link 6 to the arm it? rocks the shaft I6 its supporting slee e 15 and therefore raises and lowers the arms (1.

Normally serving as a part of the tractor I is a draw'bar structure, indicated in its entirety by the reference numeral 20. The drawbar 20 can-- prises right and left hand generally h -shaped arms 2| and 22 and a transverse par 23 rigidly secured, as by welding, to the rear endportions of the arms 2: and 2:2. An attaching hi 241s welded to the central portion of the transverse bar 23 and at its forward endcarriesan sp is ture 25to receive a pin 25 or the like by we h various implements may be connected to the trad tor drawbar 26, usually but not necessar y for generally lateral swinging movement relative thereto. The im iementwnicn illfitfats principles of the present invention is 'adaptdto be connected to the tractor drawbar 20 attli point 25 for'lateral swinging movement as will be explained :below in detail. Therromporudnsof the drawhar arms 21 and 22 extend generally downwardly,- the main portions of the arms extending over and rearwardly of the tractor rear axle structure 5. The lower ends of the drawbar arms 2| and 22 are apertured and thu receive drawbar studs 21 which are carried by the tractor rear axle drop housings 28, whereby the drawbar 2|) is mounted on the tractor at the rear thereof for generally vertical swinging movement.

The implement which I have chosen to illustrate the principles of the present invention is indicated in its entirety by the reference numeral 30 and comprises a single bottom plow connected to the tractor drawbar in short coupled relation. The plow comprises frame means in the form of a plow beam 3| formed generally as a fore and aft extending shaft member having a rear flattened section 32 to which the upper end of a plow standard 33 is connected, as by a pair of attaching beam brackets 34. The lower end of the standard 33 carries a plow bottom 35 of conventional construction. The forward portion of the plow beam 3| is mounted for rocking movement about a generally fore and aft extend ing axis in a supporting bracket structure indicated in its entirely by the reference numeral 38. The supporting bracket structure 38, preferably in the form of a casting, comprises a main plate section 4|, a generally longitudinally extending sleeve section 42 and a pair of laterally spaced transversely extending short sleeve sections 44 and 45. The plate section 4| is connected rigidly to the longitudinally extending sleeve 42 by reenforcing Webs 46 and 41. The bracket member 38 also includes an upstanding strut portion 5| and a lateral extension 52 which is joined to the right hand short sleeve section 44. The rear portion of the sleeve section 42 includes an upwardly extending apertured lug 54, and forwardly thereof the bracket member 38 is provided with an apertured boss section 55 (Figure 1) which is drilled and tapped, as at 56. Similarly, the lateral extension portion 52 is also provided with a boss portion 58 that is drilled and tapped so as to receive a threaded stud 59. The latter member serves to secure a laterally inwardly and upwardly extending brace strap 6|, the upper end of which is connected by a transverse bolt 62 to a vertically extending bracket member 63, the lower end of which is secured by bolts 64 to the forward portion of the strut section 5|. A rear diagonal brace 66 is connected at its upper end to the members 6| and 63 by the bolt 62 and at its lower end is connected by a bolt 5'! to the lug 54 of the casting member 4|. Thus, the bracket structure 38 just described is a rigid part and receives the front portion of the plow beam 3| for limited rocking movement therein.

,The beam 3| is held against rearward displacement relative to the bracket section 38 by means of a colter clamp unit indicated in its entirety by the reference numeral 19. The colter itself is of generally conventional construction, including a colter disk 1! mounted for rotation in a colter shank 12 which at its forward end is connected by suitable clamping means 13 to a short shaft 14 carried in a downwardly and forwardly extending bar 15. The upper or rear end of the bar 15 is welded or otherwise firmly fixed to a vertical shank 16 having a keyway or groove 1'! therein.

The colter clamp unit 70 comprises three members 8|, 82 and 83. The clamping member 8| has a first socket section 86 so as to fit against the front end of the plow beam 3|, and this section 86 is formed with a groove 81 therein to receive the heads of a pair of bolts 88 by which the member 82 is connected to the member 8|. The latter has a colter shank receiving groove 9| disposed generally between the bolts 88, and the cap 82 is provided with a rib 92 to seat in the groove l! in the colter shank '16. The member 8| is also provided with a pin 94 extending into the semi-cylindrical shaft-receiving groove 81, the plow beam 3| having an opening 95 to receive the pin 94. The member 3| is clamped to the front end of the plow beam 3| by the clamping member 83. The latter member includes apertured ears 9'! and a semi-cylindrical shaft-receiving section 98, together with a laterally outwardly directed arm extension 99. A pair of bolts ||l| extend through the lugs 97 and through apertured lugs 92 formed on the member 8|, and tightening the bolts ||l| effectively secures these members to the front end of the plow beam 3|, with the pin 94 disposed in the beam opening 95. The bolts 88, the heads of which nest in the transverse groove 81 so as not to interfere with the clamping of the member 8| against the beam 3|, extend laterally outwardly and receive the clamping cap member 82.

It will be noted that the pin 94 locates the clamping member 8| with respect to the plow beam 3| and that the rib 92 on the clamping member 82 locates the upper end of the colter bracket 16 relative to the clamping unit 10. The parts are so arranged that the colter bracket shank I6 is always disposed with its axis extending generally vertically in or adjacent the plane of the landside of the plow bottom 35, but by loosening one of the bolts 88 and tightening the other, the cap member 32 may, within limits; be readjusted to turn the colter bracket shank 16 about its generally vertical axis, thus shifting the front end of the colter bracket 15 laterally toward the right or left so as to dispose the colter 7| in the proper position relative to the plow point. Similarly, the position of the arm 99 relative to the plow beam 3| may be varied by loosening one of the bolts HJI and tightening the other. The arm 99 forms a part of the means providing for automatically leveling the plow bottom 35 in its different depths of operation and such means will be described later.

The bracket structure 38 is adapted to be connected with the tractor drawbar 20 by quick detachable means that is indicated in its entirety by the reference numeral H0. The short sleeve sections 44 and 45 of the bracket casting 4| receive a cross shaft H2 which is fixed therein, as by a pin P or the like (Figure l). The shaft H2 is slidably mounted in the rear apertured ends of a pair of forwardly extending lugs H4 and I 5 that are welded to the rear portion of a forwardly extending attaching member in the form of a saddle H6 having upper and lower generally triangular sections H1 and 8 forming therebetween a socket to receive the cross member 23 of the tractor drawbar 29. The member H6 engages the upper and lower sides of the cross member 23 along the length of the latter, as will be seen from Figures 1 and 4, and thus contacting the bar 23 at laterally spaced apart points the member H6 is held against tilting movement relative to the bar 23 about a generally longitudinally extending axis. The shaft H2 and associated parts form transverse hinge means connecting the forward portion of the implement frame means with the attaching member H5 which swings bodily with the tractor drawbar 20. The forward portions of the upper and lower saddle member sections Ill and H3 are apertured to receive the draft pin that is insertable through the openingv in the draft lug 24 formed on the'tractor drawbar 2B. The saddle member [It is dimensioned so that when the pin 26 is in place the saddle member H5 may swing laterally relative to the tractor draw" bar through a limited extent, and hence the plow bottom 35 and associated frame .structure may also swing laterally relative to the tractor, the plow beam hingedly connected with the saddle member I I t'through the shaft I l2 whereby the blow bottom is held against movement about a fore and aft extending axis except as permitted by the movement of the plow beam 3I in thebracket sleeve 42.

The member 63 of the bracket structure '38 extends upwardly and receives a pivot pin I25 by which a swivel member 126 is connected therewith for generally vertical movement relative thereto, and the forward portion of the swivel member I26 is bifurcated so as to form two vertically spaced sections it! and E28 which are apertured to receive a vertical pivot pin I29 by which the rear end of a link member, indicated in its entirety by the reference numeral I38, is connected therewith for lateral movement with respect thereto. The forward end of the link member I30 includes a bifurcated attaching section i32 apertured to receive a quick detachable pin I 33 by which the front portion of the link member l3t may be connected with a pivot block 233 supported for rocking movement by laterally directed trunnions 35 in a pair of apertured lugs I35 fixedly attached to the central portion of the sleeve member It on the tractor. It will be noted that in operation the link member {Si is stressed in compression while the tractor draw.- bar 29 is stressed largely in tension, and the plow may be raised and lowered by virtue of a pair of links IS'l-that are pivotally connected at their upper ends to the lift arms ii and at their lower ends are pivotally connected to the side arms 2i and 22, of the tractor drawbar 28 by pivot studs B3B.

The link member I30 preferably is made so as to incorporate therein an overload release unit, and to this end the link member 533 comprises two arm sections it! and I 32 pivotally interconnected together by a transverse pivot bolt 53. The inner end of each of the link members It! and M2 is formed with arcuate cam sections in the form of lugs his and sockets M5 interconnected by angledcam edges M6. As best shown in Figure l, the lugs on one link member normally interlock with the sockets on the other member, and the parts are held in this normally interlocked relation by virtue of a pair of resilient members Ml, preferably formed of rubber or. rubber-like material, which are clamped underneath clamping washers Itil and held in tightly clamped relation by the pivot bolt Hi3. As best shown in Figure 2, the arms and link members MI and I -l2 are arranged so that the pivot pin his lies slightly above the: line, connecting the pivots i255 and I35 between the link member 53d and the plow bracket and tractor support, respectively. However, if the plow bottom should engage under a stone, strike a stump or other obstruction, or otherwise be sub jected to an overload, the links Ml, M2 will break or buckle upwardly. permitting the plow. bottom to swingv away from the obstruction.

In order to have the plow bottom of an integral plow operate in a level position at different depths-cicpcratiqn while. the racto s operated with on rrear whee in theif rrow; and. one whee on theland, it is usually necessary to provide some means for adjusting the position of the plow bottom relative to the tractor about a generally fore and aft extending axis. This action is accomplished automatically, according to the principles of the present invention, by virtue of the angling arm 98'on the colter clamping member 83 and a pair of cooperating arms I5I, secured-as by welding, to the lug H4 on the saddle member H6. It will be noted that the :two arms-LEI have their ends disposed on opposite sides ofa ball shaped section I53, formed on therouter end of the arm 99 and that the arms I5I arecdisposed forwardof the axis, defined-by the shaft H2, about which the plow as a unit hinges or pivots with respect to the saddle member IIB when the tractor drawbar 2.0 is raised and lowered. The action of these parts is such thatwhen the drawbar 29 of the tractor isvmoved downwardly, so as to cause the plow bottom to operate at an increased depth, the arms lEI acta'gainst the, arm so as to swing i the plow beam 3| in the sleeve 42 in a counterclockwise direction, looking at the outfit from the rear, thus swinging the plow bottom 35into such position that when the right hand wheel of the tractor operates in the furrow at the new depth the plow bottom will operate in a level position. The converse is true if, for example, the drawbar 2i israised to decrease the depth of operation of theplow, and when the drawbarifl is raised into' its uppermost positionior transport, 'theplow bottom 35 is swung laterally inwardly toward a central position behind the tractor.

The plow may be adjusted laterally relative to the tractor by shifting the bracket structure 38 laterally along the shaft H2, and in order'to maintain the desired lateral adjustment, 1 have provided a plurality of abutment links ibt pivotally mounted on a stud bolt :55 threaded into the apertured andtapped boss 55 on the bracket casting ti. I-he outer end of the bolt its receives a spacing link {til-which is disposed on the outer end of :the shaft 2 i2 that fined to one or the other of the short sleeve sections ti l, I it so as to be movable with the plow relative to the saddle member H6 and associated parts. Preferably, the outer end of the shaft IE2 is tapped to receive a stud I58. A washer its is disposed between the head of the stud i533 and the forward end of the link B51. Theforward end of each of the abutment links $55 is formed with a notch I6! whereby the links I55 may be swung upwardly or downwardly away from or toward the shaft i It and maybe clisposedon one or the other of the sides of the lug H5, thereby coop crating with the lug H5 to maintain the plow: in its position of lateral adjustment. If, for example, all of the abutment links I55 were disposed on the'inside of" the lug 'i i5,.the plow is at its laterally outer limit of adjustment, as shown in Figure 1'. If it should be desired to move the plow laterally inwardly, as'to increase the width of plowing, one or more-of the links it may be raised-away from the shaft M2, the plow shifted laterally relative to the saddle member Hi5 and the'links then dropped down onto the shaft Hi; betweenthe lug H5 and the outer link l-za'l.

While I have shown and described above the preferred'structure in which the principles of the present invention have been incorporated, it is to be understood that my-invention'is not to 1 be limited to the particular details shown and described above, but that, in fact, widely diiierent means may be employed in the practice of the broader aspects of my invention.

What I claim, therefore, and desire to secure by Letters Patent is:

1. The combination with a tractor having a hitch member that is laterally and torsiona-lly rigid and is connected with the tractor for generally vertical swinging movement, said hitch member including a traverse bar of a plowing unit, means for connecting said plowing unit with said hitch member for movement relative thereto about a generally extending fore and aft axis and a generally transverse axis, said means including a bar-receiving member adapted to snugly receive said bar so as to be constrained to swing generally vertically therewith, a plow supporting structure pivotally connected with said bar-receiving member for movement relative thereto about a generally transverse axis, and frame means swingably connected with said supporting structure for movement relative to the "latter about a generally fore-and-aft extending axis, a first part rigidly connected with said barreceiving member at a point spaced from said transverse axis, a second part fixed with respect to said frame means and disposed adjacent said first part, and interconnecting means acting between said parts whereby movement of said supporting structure relative to said bar-receiving member about said transverse axis acts to rock said frame means about said fore-and-aft extending axis, whereby when the plowing unit moves about said transverse axis relative to said hitch member, said unit is automatically shifted about said fore and aft extending axis, for leveling the plowing unit at difierent depths of operation.

2. The combination with a tractor having a hitch member that is laterally and torsionally rigid but connected with the tractor for generally vertical swinging movement, of a plowing unit, means for connecting said plowing unit with said hitch member for movement relative thereto about a generally fore and aft extending axis and a generally transverse axis, means swingable vertically with said hitch member and extending alongside said plowing unit to a point spaced fore and aft from said transverse axis, and means on said unit engageable by said swingable means for turning said plowing unit about said last mentioned axis in response to vertical swinging of said hitch member about said transverse axis relative to said plowing unit, for leveling the plowing unit at different depths of operation.

3. An integral plow adapted to be connected to a tractor having a generally laterally rigid vertically swingable drawbar, the latter including a pair of generally vertically swingable side arms and a rear transverse bar rigidly fixed at its ends to the rear portions of said arms, a plow beam, means for connecting said beam with said transverse bar, including an attaching structure pivotally connected with said transverse bar for pivotal movement relative thereto about a generally vertically extending axis disposed relatively closely adjacent said transverse bar, a plow bottom fixed to said plow beam, a link disposed above said drawbar and connected at its forward end to react against the tractor, means pivotally connecting the rear end of said link with said attaching structure for movement with respect thereto about both vertical and horizontal axes, and means connected with the drawbar for raising and lowering the latter and thereby raising and lowering said plow bottom.

4. An implement adapted for use with a tractor having a generally vertically swingable drafttransmittin means and a generally fore-and-aft extending thrust link disposed above said drafttransmitting means and swingably connected at its forward end with the tractor, said implement comprising a plow beam, an attaching structure in which said plow beam is rockably mounted for movement relative to said structure about a generally fore-and-aft extending axis, said attaching structure adapted to be pivotally connected with said draft-transmitting means for pivoting movement relative thereto about a generally transverse axis, means for pivotally connecting the upper portion of said attaching structure with said thrust link, a plow bottom fixed to said plow beam, a part connected to pivot relative to said attaching structure when said draft-transmitting means swings relative to said attaching structure, a part fixed to said beam and engageable with said first mentioned part, whereby when said attaching structure pivots relative to said draft-transmitting means, said plow beam is rocked about said fore-and-aft extending axis relative to said attaching structure, and means for raising and lowering said drawbar for raising and lowering said plow bottom.

5. The combination with a tractor having a rear drawbar swingable generally vertically and including a transverse section, of an agricultural implement unit including ground working means, an attachment member pivotally connected with said unit for movement relative thereto about a generally transverse axis, said attachment member comprising means embracing the transverse section of said tractor drawbar at laterally spaced apart points so as to hold said unit against movement relative thereto about a generally longitudinally extending axis and means pivotally connecting the attachment member with the drawbar so as to provide for lateral movement of said attachment member relative to the tractor drawbar about a generally upwardly extending axis, an upwardly extending bracket carried by said unit, and a compression-resisting link operatively connected at one end with the upper portion of said bracket and adapted to be connected at its other end with the tractor.

6. The combination set forth in claim 5, further characterized by means for connecting said one end of said link and the upper portion of said bracket, said means including parts accommodating relative movement about a generally vertical axis adjacent the vertical axis about which said attachment member has movement relative to the tractor drawbar.

7. The combination set forth in claim 5, further characterized by means for connecting one end of said link with the upper portion of said bracket, and means for connecting the other end of said link with said tractor for lateral swinging movement relative thereto.

8. The invention set forth in claim 5, further characterized by a generally vertical pivot pin connecting said attachment member with the tractor drawbar and a generally vertical pivot pin connecting the forward end of said link with the tractor, both of said pins being readily detachable.

9. The combination with a tractor having a generally vertically swingable drawbar, of an implement attachment comprising a part pivotally connected with said drawbar for movement relative thereto about two angularly related axes, a member, means for connecting said member with said drawbar to swing therewith relative to said part when the drawbar is swung relative to the tractor, an arm fixed to said part and extending generally at right angles to one of said axes, and cooperating arm means on said member engagable with said first mentioned arm for swinging said part about said one axis.

10. In an agricultural implement, a generally vertically swingable raising and lowering member, a bracket hingedly connected therewith for movement about a transverse axis and including a generally fore-and-aft extending sleeve section, a plow beam rockably mounted in said sleeve section for movement about a fore and aft extending axis, and interengaging arms fixedly connected to said beam and said. member, respectively, said arms being spaced, respectively, from said transverse and fore-and-aft extending axes, for rocking said beam by movement of said member relative to said bracket.

11. In an agricultural implement, a generally vertically swingable raising and lowering memher, a bracket hingedly connected therewith for movement about a transverse axis, a sleeve fixed to said bracket and extending in a generally fore and aft direction, a plow beam rockab-ly mounted in said sleeve, an arm fixed to the front end of said plow beam and extending generally radially outwardly relative to the axis of rocking of said plow beamin said sleeve, and means fixed to said raising and lowering member at a point spaced from said transverse axis and engageable with said arm for rocking the plow beam in said sleeve when said raising and lowering member is shifted about said transverse axis relative to said bracket.

12. The invention set forth in claim 11, further characterized by a colter bracket fixed to the front end of said plow beam, a colter carried in said colter bracket, a plow bottom fixed to the rear end of said plow beam in fixed relation with respect to said colter, said arm being adjustably mounted on said colter bracket.

13. For use with a tractor having a hitch that is laterally and torsionally rigid but connected with the tractor for generally vertical swinging movement, the improvement which includes an agricultural implement connectible with said hitch and comprising frame means, an attaching member havin a forwardly facing socket, pivot means for connecting said attaching member with said hitch for movement relative thereto about a generally vertical axis, the socket of said attaching member being adapted to snugly receive the rear portion of said hitch whereby said attaching member is bodily swingable with said hitch, transverse hinge means connecting said implement frame means with said attaching member, an upwardly extending bracket fixed to said implement frame means, a rigid compression-resisting link adapted to be connected at its forward end with the tractor, and pivot means connecting the rear end of said link with the upper portion of said bracket for relative movement between the bracket and link about generally transverse and vertical axes, the generally transverse axis being substantially parallel to the axis of said transverse hinge means and the last mentioned vertical axis lying adjacent said first-mentioned vertical axis.

14. An agricultural implement as defined in claim 13, further characterized by means acting between said frame means and said attaching member for holding said frame means in different positions of lateral adjustment along the axis of said hinge means.

15. An agricultural implement as defined in claim 14, further characterized by said frame means including a generally fore and aft extending part shiftable relative to the frame means about a generally fore and aft extending axis, and means connected to move with said attaching member and acting against said part for shifting the latter about said last-mentioned axis.

16. For use with a tractor having a lower draft means that is connected with the tractor for generally vertical swinging movement and an upper compression link also connected with the tractor at its forward end for generally vertical swinging movement, an agricultural implement connectible with said draft-transmitting means and said compression link, said implement comprising a generally vertically extending attaching structure, means pivotally connecting the rear portions of said draft-transmitting means with the lower portions of said attaching structure, means pivotally connecting the rear portion of said upper compression link member with the upper portion of said attaching structure, means on the lower portion of said attaching structure forming a generally fore-and-ait extending sleeve section, a beam member mounted for rocking movement in said sleeve section and extending in a generally foreand-aft direction, a ground-working tool fixed to the rear portion of said beam member, an arm fixed to the forward portion of said beam member, a second arm engageable with said first arm and movable relative to said attaching structure, and means for connectin said arm with said draft-transmitting means so as to be swingable vertically therewith, said last-mentioned arm engaging said first arm so as to rock said beam about a fore-and-aft extending axis in response to swinging movement of said drafttransmitting means relative to said attaching structure.

KEITH R. SCHOLFIELD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,366,842. Smith Jan. 25, 1921 1,688,615 Daniel Oct. 23, 1928 1,807,731 Ehricke June 2, 1931 1,864,639 Crezee June 28, 1932 1,980,470 Brown Nov. 13, 1934 2,249,861 Silver July 22, 1941 2,302,502 Morkoski et al Nov. 17, 1942 2,319,670 Ego May 18, 1943 2,345,741 Foulke Apr. 4, 1944 2,351,473 Benjamin June 13, 1944 2,379,225 Fraga June 26, 1945 2,398,147 McKay Apr. 9, 1946 2,438,553 Fraga Mar. 30, 1948 2,567,736 Silver Sept. 11, 1951 FOREIGN PATENTS Number Country Date 628,907 Great Britain Sept. 7, 1949 

